The present invention relates to a method for sterilizing the water circuits of dental apparatus and to the dental apparatus implementing the method.
In the manufacturing of dental equipment, one of the fundamental parts, if not the “heart”, of a dental unit is its water and air circuit, where the water line supplies fluids used by dental equipment and patients (water or physiological saline for tumblers and handpieces), or consumer units (swilling water for the spittoon), while the air line is used for certain items of equipment (air spray handpieces, cooling air and driving air).
With increases in general standards of hygiene and with dental apparatus and equipment becoming more and more “fragile”, several design solutions have been found for the water and air circuits of dental units, not only to guarantee their efficient operation and durability but also to maintain the sterility of the conduits during patient treatments. Considering that the basic structure of these fluid circuits comprises a first main line supplying water from the mains, and a second main line supplying air from an external source (compressor), each of which has a plurality of branches leading to the operating and accessory equipment of the dental unit, different systems have been designed on the basis of different methods aimed at improving the functioning and disinfection of these fluid lines or parts of them.
In particular, the present specification focuses attention on the water line which is disinfected according to two different methods, one with a continuous cycle and the other with a discontinuous cycle, and both requiring additional devices to be fitted to the basic structure of the circuit.
The present specification is concerned in particular with the solutions based on the discontinuous disinfection/sterilization cycle. In this type of cycle, as disclosed in patent publications EP-111.249 and EP-317.521 (the latter being by the present Applicant), the mains water supply is shut off, and a dedicated branch equipped with an independent tank is used to feed sterilizing liquid into the conduits that supply water to the handpieces.
After a preset time, depending on the quality of disinfection/sterilization required and the properties of the sterilizing liquid, the line is opened again and the sterilizing liquid drained out.
The drainage of the sterilizing liquid is performed by flushing water (or a user fluid) supplied by the main line (or by a dedicated line) and opening the control valves on the handpieces so that the water or user fluid expels the sterilizing liquid, rinses the water line and flows out into an appropriate drain.
Although this method, which has been used on dental units for some time, has proved to be very effective and practical, the Applicant, in line with a policy of continual improvement of dental unit sanitizing procedures, has continued conducting research and development targeted to improving safety by adding innovative elements and features to sterilizing procedures in order to enhance the performance of the sanitizing products used and, consequently, to increase the safety of the dental equipment.
The aim of the present invention is therefore to provide a dental apparatus sterilizing/disinfecting method that is safe and practical, enhances the performance of the products used and at the same time reduces down time during changes of fluids.